IT’S war over the body of Christian Brando, who died Saturday in Los Angeles, as authorities try to figure out what killed the son of the late legend Marlon Brando. An autopsy yesterday listed the cause of death as deferred, pending toxicology tests to find out if he had prescription or other drugs in his system – and whether a medical condition was involved. The autopsy was requested “based on his past drug history,” the LA county coroner said. Christian’s estranged mom, Anna Kashfi, requested it.

Meanwhile, his ex-wife has teamed up with Kashfi to battle Christian’s girlfriend and adopted siblings over who will get his remains and what will be done with them.

The ex, Debra Presley, married him in 2004 – for all of three months – and claims to be the illegitimate daughter of Elvis.

“These two want to take the remains to Washington and have him buried because he used to live there,” said Keith Fink, a lawyer for Donna Geon, Brando’s girlfriend of three years.

“They don’t want his girlfriend or the siblings to even see the body, for no reason at all.”

But Geon says Christian’s wishes were to be cremated and have his ashes spread in Franklin Park in Los Angeles, the same place his father had some of his ashes spread.

Christian’s half-sister, Rebecca Brando, and half-brother, Teihotu Brando, along with Geon, hired Fink to assist them in getting rights to the body.

Fink plans to file a motion in LA Superior Court on the trio’s behalf to have the corpse released to them once it leaves the county coroner’s office.

“Their grievance is that they’re the ones who loved Christian. They want his remains to stay in California and they want to do what he wished,” said Fink.

“Meanwhile, the mortuary complained to me that Anna ignored them when they explained how the body should be properly clothed and cared for. They are just being petty, vindictive, small people who border on loony toons.”